Isotope Hydrology of Groundwater in Bangladesh: Implications

1,47

MB

for Characterization and Mitigation of Arsenic in Groundwater

65

stron

4680

ID

International Atomic Energy Agency

2000

rok

TABLE OF CONTENTS

1. INTRODUCTION 1

1.1 Background 1

1.2 Objectives 1

1.3 Scope of the Study 2

1.4 Principles of Isotope Hydrology 2

2. GEOLOGY AND HYDROGEOLOGY 7

2.1 Physiography, Structure and Stratigraphy 7

2.2 Climate 8

2.3 Hydrogeology 8

2.3.1 Classification of Aquifers 8

2.3.2 Historical Trends in Water Levels 10

2.3.3 Recharge to Groundwater 10

2.3.4 Groundwater and Surface Water Relationship 27

2.3.5 Groundwater Quality 27

3. ANALYTICAL RESULTS 31

3.1 Arsenic 31

3.2 Stable Oxygen and Hydrogen Isotopes 32

3.3 Tritium and Carbon-14 34

4. DISCUSSION 38

4.1 Isotopic Signatures of Shallow and Deep Groundwater 38

4.2 Implications for Arsenic Mitigation Actions 40

4.2.1 Arsenic in Deep Aquifers 40

4.2.2 Safety of Deep Groundwater 41

4.2.3 Mechanism(s) of Arsenic Mobilization 45

5. CONCLUSIONS 46

BIBLIOGRAPHY 47